Refrigeration



Jan. 9,1945. L BUR QF RABE I {2,366,955

REFRIGERAT ON Filed Sept. 20,1941

. ag'aamv A; ATTORNEY.

Patented Jan. 9,1945

REFRIGERATION Henry A. Burggrabe, Evansville, Ind., assignor t o Servcl, Inc., New York, N. Y., a corporation of Delaware Application September 20, 1941, Serial No. 411,604

3 Claims.

. action of vapor conservatively produced.

The single figure of the drawing shows more or less diagrammatically a heat transfer system embodying the invention.

a conduit 28 to the header I8 in the refrigerator Alongside of transfer vessel 23 there is a pressure vessel 29. An opening in the top of .transfer vessel 23 controlled bya valve 30 is connected by a, conduit 3| to the top of pressure vessel 29. An opening in the top of vessel 29 controlled by a valve 32 is connected by a conduit 33 to conduit 26. The bottom of vessel 29 is connected by a conduit 34 to conduit 24. Between conduit 34 and the bottom of vessel 29 is connected a check valve 35. Check valve 35 permits flow of liquid only in At a lower elevation, such as in the basement of a store, there is -located refrigeration apparatus including an evaporator or cooling element Ill. The evaporator I0 is a part of a refrigerating apparatus like that shown and described in Patent No. 2,207,836 of A. R. Thomas to which reference may be had for explanation of operation of the system.- The disclosure of said patent is hereby incorporated in the present specification. The evaporator I 9 contains a pipe coil II. Above pipe coil II is a liquid distributor I2. An inlet conduit I3 is arranged to direct liquid refrigerant into distributor I2. The liquid refrigerant is deposited by distributor I2 onto coil II. The liquid descends over the outside of coil II, evaporating and diffusing into an auxiliary pressure equalizing fluid such as hydrogen; The evaporation of liquid onv the outside of tube II produces cooling of fluid within the-tube. ydrogen enters evaporator Io through a conduit l4 and flows to the top of the evaporator through a central pipe IS. The mixture of refrigerant vapor and inert gas leaves the bottom of evaporato I0 through a conduit I6. I The upper end of evaporator coil II is connected by a conduit H to a header I8. A finned heat transfer coil I9 is connected to header is, and together therewith forms a second evaporator or cooling element. The evaporator I9 is located in an insulated refrigerator storage compartment 29 which may be a display case'or walk-in cooler or the like on anupper floor. of the store. The

: lower end of evaporator coil- II 'is connected by I a conduit 2| to the top of a vessel 22. Below vessel 22 there is a transfer vessel 23. The bottom of vessel 22 is connected by a conduit 24 to an inlet opening in the top of transfer vessel 23 controlled by a valve 25. The upper end of evaporator coil II is connected by a part of conduit I1 and a conduit 26 to another opening in the top of transfer vessel 23 controlled by a valve 21.

The bottom of transfer vessel 23 is connected by are open.

the direction from conduit 34 into vessel 29. Vessel 29 is in heat-exchange relation with a heating element 3i; which may be, for instance, theoutlet conduit for cooling water from the refrigeration apparatus.

v Valve 32 in pressure vessel 29 is operated by a float 31 so that valve 32 is held closed when float 31 is buoyed upward by liquid in vessel 29. Valves 25 and 21 and 30 are operated by a float 38 through a snap action lever mechanism 39. The lever mechanism 39 is constructed as shown so that when the float 38 is up, valves 25 and 21 are closed and valve 30 is open, and when float 38 is down, valve 30 is closed and valves 25 and 21 The above described system of conduits and vessels is charged with a volatile heat transfer fluid which may be, for instance, methyl chloride. When the refrigeration apparatus is operated as described in said Thomas patent, cooling of evaporator coil lI takes place. As a result of this cooling, vapor of methyl chloride or other heat transfer fluid is condensed to liquid in coil Il.

the circuit so that the liquid refrigerant vaporizes in the evaporator coil I9 to produce cooling of refrigerator compartment 20. Vapor produced by evaporation of liquid in the evaporator coil I9 v flows from the evaporator header I8 through conduit I! to the condenser I I.

Liquid condensate formed in condenser I I flows from the bottom end of this coil through conduit 2| into the accumulation vessel 22. Assuming that float 38 is down so that valves 25 and 21 are open, liquid flows from vessel 22 through conduit 24 into transfer vessel 23. During flow of liquid into transfer vessel 23, which may be generally referred to as a filling period, the pressure in vessel 23 is equalized with the pressure in the rest of the system through opening valve 21. and conduit 29. During this time, valve 3011s closed so that transfer vessel 23 is cut 011. from the pressure vessel 29. Liquid rises in vessel 23 and raises float 38 until the snap action leverage is operated to open valve 38 and close valves 25 and 21. Thereupon vessel 23 is connected to vessel 29 by way of conduit 3|. Vessel 29 is supplied with liquid from accumulation vessel 22 by way of conduit 24 and conduit 34. Vessel 29 is filled with liquid to such a level that float 31 closes valve 32. Since conduit 36 contains water which has been heated by the refrigeration apparatus, liquid in vessel 29 is maintained at such a temperature that its vapor in the upper part of vessel 29 and conduit 3| is maintained at a high pressure. When this high pressure is in existence, valve 32 is held closed even through float 31 drops due to decrease in liquid caused by vaporization.

When vessels 23 and 29 are connected through conduit 3| as described above, the high pressure in vessel 29 is communicated to vessel 23. This pressure causes liquid in vessel 23 to be diplaced from the bottom of this vessel through conduit 28 into the header l8 of the elevated evaporator. As the liquid level falls in vessel 23 during what may be generally termed the transfer period, float 38 descends until it operates the snap action leverage to open valves 25 and 21 and close valve 30. As float 38 descends, it actually only sets the valve operating mechanism 39 so that valves 25 and 21 may open when the pressure in vessel 23 is relieved to the system through conduit 28. During periods of high pressure in vessel 29, check valve 35 prevents flow of liquid out of this vessel. At the end of each transfer period, when valves 25 and 21 open, vessel 23 is vented through conduit 26 so that a filling period starts.

During the time that the pressure in vessel 23 is relieved due to flowing of liquid out of conduit 28, valve 30 is still open so that the pressure in vessel 29 is also temporarily relieved. This permits valve 32 to open in case float 31 is down. When valve 32 is open, liquid is replenished in vessel 29 through conduit 34, raising float 31 to again close valve 32. Conduit 26 and valve 21 provide a vent for vessel 23 during the time that liquid is flowing into this vessel.

Valve 30 being closed, vessel 29 is cut ofl from the system when valve 32 closes so that pressure builds up in vessel 29 to be available for the next transfer period.

Various changes and modifications may be made within the scope of the invention as set forth in the following claims.

What is claimed is:

1. A system for effecting cooling at an elevation above a source of refrigeration including an evaporator at the upper elevation, a condenser arranged to be cooled by said source of refrigeration, a conduit for vapor from said evaporator to said condenser, a vessel connected to receive liquid condensate from said condenser and deliver the liquid condensate to said evaporator when the pressure in said vessel is increased sufliciently to force the liquid therefrom upward to said evaporator, a second vessel connected to receive liquid condensate from said condenser, a conduit for vapor from said second vessel into said first vessel, valve mechanism in said first vessel operative responsive to level of liquid therein to control communication between said vessels, and valve mechanism in said second vessel to control admission of liquid thereinto.

2. In apparatus of the character described, a transfer vessel, a heated chamber, a conduit for vapor from said chamber to said vessel, conduits for separately conducting liquid to said vessel and to said chamber, a first float operated valve mechanism for controlling entrance of liquid and vapor into said vessel, and a second independent float operated valve mechanism for controlling entrance of liquid to said heated chamber.

3. In apparatus of the character described, a transfer vessel from which liquid .is displaced to a higher elevation when the pressure in said vessel is raised to the necessary value, a heated chamber connected to supply vapor for increasing the pressure in said vessel, and valve mechanism for preventing flow of vapor from said heated chamber to said vessel and prevent increase of pressure in said vessel except during a period in which liquid is forced from said vessel.

HENRY A. BURGGRABE. 

